Eation



H. R. DAVIES.

IGNITION SYSTEM. APPLICATION FILED APR. 8, 1919.

1,372,650. Pa ented Mar- 22, 1921.

. IN V EN TOR, Henry R. Davies f BY 3;

I I I 4 n I y I "vision of means for utilizing for ignition UNITED s unt: n. 'navmsor TOLEDO, oiiiojassicnon 'ro mnusTmAr. gamma CORPO- P EmeFFwE narrow; or onnno, onto, IACORPORATION or DELAWABE.

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To all eoh omit may concern: Be it known that I, HENRY R. Davies, a citizen of the United States, residing at Toledo,'in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Ignition Systems, of which I declare thefollowing-to be. a full, clear, and exact description.

This invention relates to improvements in systems for generating'electric current with power furnished by an internal combustion engine, and for utilizing the current, at least partially, in starting the engine and in furnishing ignition thereto.

One ob'ect of'the. nvention is the propurposes, current from a comparatively high voltage dynamo-electric machine without condensers- I Another object of theinvention is the prothe use of resistance coilsor high capacity vision of means for supplying a relatively l-sp'eeds. I

Othercbjects will appear as I proceed strong currentto the ignition system, while the engine is being started.

Another object is the provision of means for supplying to the'ignition circuit from the generator or motor-dynamo, a current which is stronger in proportion to the total current generated at comparatively low engine speeds than at high engine speeds.

Another object is to combine means for taking the ignition off the third brush of the generator or motor-dynamo, and means for taking current for the shunt field of the ma- .chine 01f the third brush also, which. combines with the third brush regulation of the field, producing acomparatively high currentoutput for the machine at low speeds,

a third brush ignition circuit making a larger part of the total current output available for ignition at low speeds than at high with the description of that embodiment of the invention, which for the purposes of the present application, I have illustrated in the accompanying drawing, in which Figure I is a diagram of apparatus and electrical connections showing my invention as applied to a motor-dynamo.-

Fig. II is a similar view showingthe invention applied to a two-unit system, that is one in which the motor and generator. are separatemachines.

Fig. III is a view similar to Fig. I, but

Specification of Letters Pate t. P t t d Man 2'2, 192 Application filed April 8, 1919. Serial. No. 288,507.

showing the motor-dynamo field extending across the main brushes instead of between one of said main brushes andan auxiliary brush.

Similar reference characters refer to similar parts throughout the views. 4

In each of the figures I have shown diagrammatically at 10 a storage battery-electric machine, which in Figs. I and III is illustrated as a motor-dynamo 15, while in F 1g. '11 it is shown as a generator 16, a separate machine 30 being employed as a motor;

In Figs. I and II the shunt, field 17 is taken ofi the third brush 90f the dynamo electric machine, butv in Fig. III, I have'shown a shunt field 18 connected across the main brushes 7 and 8 of the machine.

' In each of the figures a circuit wire 19 i 7 leads from the third brush 9 to the primary winding 20 of an ignition coil of a gas engine, operatively connected with the motordynamo in Figs. I and 'III and with the I motor in Fig. II, as indicated by the diagrammatically illustrated shaft 21. The other side of the primary coil is electrically connected by a circuit wire 22 with the circuit wire 13 and thence to the main brush 7 L of the machine.

v In' the primary ignition circuit, an interrupter 23 and 'a condenser 24 are arranged in parallel, for purposes well The sec-- known to those skilled in the art. ondary winding of the ignition coil is-indi cated at 25, it being connected through the conductor 26 with a current distributer27' from which the high'tension current is led to spark plugs 28 and thence to ground. The other side of the secondary winding'is connected to ground-at 29.

In Fig. II the engine starting motor. 30 is bridged across the linewires 13,14 when switch 31 is closed. The operation of a plungerv 32 to close the switch 30 simultaneously I closes a switch 33 inthe circuit'wire 13, but

the parts are so arranged that the switch 31 may be opened without opening the switch 33. 195

In this figure is shown, also, a battery cuteout of 'a common design. One coil 34c of thec'utout is connected in a shunt 35 across the line wires 13, 14. The second coil 36 is connected in the vwire'13 when the cut-out armature 37 is in attracted position. When the generator 16 is producing currentof a certain minimum voltage, the coil 34; sets up sufficient magnetism to attract the armature 37 thus closing the generator ignition circuit. Now that the armature l7'is attracted it is held down by coil 36 as well as coil 34, and hence the circuit is not broken until the voltage decreases to a point somewhat lower than that required to close the; cut-out. In this way, constant opening and closing of l the .cut-otit at a certain engine speed is avoided.

' known in the art.

Regulation of a shunt field generator by means of a third brush, to which one terminal of the field is connected, is old and well It is also old, as shown in Patent'No. 801823 to E. J. Berg, to take current for an ignition'circuit from a third brush, in order to obtain current of a proper voltage from a comparativelyhigh voltage machine. So far as I am aware however, it is novelto take both the ignition current and the field from a third brush, and by doing so to obtain better regulation of the ignition than could be obtained by the use of either one alone. I also believe it to be novel to employ a third brush as one terminal of the ignition circuit of agas engine, operatively connected to a motor-dynamo. In this latter connection a new and valuable result is ob- Y tained, namely a stronger ignition current both of the switches. 31 and 33 close.

' begins to operateunder its own power, after being. revolved by the motor 30, and after it has acquired a predetermined speed, the voltage across the main brushes 7 and 8 of the generator rises sufficiently to cause the coil 34 of the cut-out to attract armature 37 and thereafter the ignition circuit draws its current from the generator instead of the battery. At the slower generator speeds, distortion of the field caused bythe lines of force set up in the armature is small; hence the voltage drop across the brushes 7 and 9 is not much diminished by distortion. At greater speeds however, the distortion increases, the axis of commutation moving toward the right under the brush 7, and reducing correspondingly the voltage and current across the field winding 17, which in turn reduces the electro-motive force of the machine and thus the current traversing the field winding 17 and the ignition coil '20, which, by weakening the field, further reduces the electro-motive force. The third brush connection of the field winding 17 therefore tends to make the total current output of the machine greater in proportion to its speed of rotation, at low engine speeds than at high enginespeeds. Now, by connecting the ignition circuit also to the third brush, 1 utilize for ignition purposes a greater proportion of the total current output of the machine at low engine speeds than at high engine speeds.

Here the amount of field distortion determines the lationl, just as in the case of n this way the eii'ect amount of re the field win ing.

upon the ignition current of the connection' of the field circuit With the thirdbrush, and the connection of the ignition circuit with the third brush, are cumulative.

In Figs. I and III the invention is illustrated in connection with a'motor dynamo. Here, closing of the switch of the circuit wire 13 causes the dynamo-electric machine 15 to operate as a motor, drawing current from the battery 10, to start the gas engine through the operative connection 21. While a the machine is motorizing, the distortion of tween the brushes 7 and 9 is greatest at the beginning of the starting operation, and is greater at all times during motorizing than during generating by an amount corresponding to the sum of the angle of forward lead, when the machine is used as a generator, plus the angle of backward lead when it is used as a motor. The current through the primary winding 20 of the ignition coil is therefore greatest at the beginning of the motorizing of the machine 15, and proportionately greater during the balance of the timeivhile it is motorizing than while it is generating, which is hi hly desirable, as will be readily appreciatecf I am aware that the particular embodiment of my invention described, and illustrated in the accompanying drawing, is susceptible of considerable variation without departing from the spirit thereof, and therefore I desire to claim my invention broadly, as well as specifically, as indicatedby the appended claims.

I claim as my invention:

1. In combination with a generator hav- 4 l mg main brushesand an auxiliary brush, a shunt field for said generator'and an ignition circuit, said field'a'nd circuit being con battery electrically connected to said main brushes, and a shunt field and an ignition circuit connected together in parallel and interposed between said said auxiliary brush and that oneof said main brushes between which the voltage decreases as the dynamo speed increases, whereby maximum torque for the motor and maximum ignition current for the engine is obtained at starting.

3. The combination with a generator hav-.

ing a shunt field, main brushes and an auxiliary brush, of an ignition circuit having a primary winding, said ignition circuit being connected to the auxiliary brush and that one of the main brushes between which the avoltage diminishes with increase of spee 4. The combination with a motor-dynamo having a shunt field, main brushes, and an auxiliarybrush fixed on the motor dynamo so that the voltage between the auxiliary brush and one of said main brushes diminishes with an increase in speed of the motor dynamo, of an ignition circuit, said ignition circuit being connected to the main and auxiliary brushes between which the voltage diminishes with speed increase, whereby maximum ignition current is obtained at approximately lowest speeds, when the motor dynamo is functioning as a motor.

In testimony whereof, I afiix my signature.

HENRY R. DAVIES. 

